Bozić F, Lacković G, Kovsca-Janjatović A, Smolec O, Valpotić I
Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia.
J Vet Pharmacol Ther. 2006 Jun;29(3):199-204. doi: 10.1111/j.1365-2885.2006.00731.x.
Recent findings demonstrate that priming by levamisole of weaned pigs experimentally vaccinated against postweaning colibacillosis (PWC) contributes to immune protection from challenge-induced clinical disease through stimulation of the mesenteric lymph node cells that participate in cell-mediated immunity. With the objective of better understanding the mechanisms by which levamisole induces protective mucosal cell-mediated immune response to vaccination against PWC, it was tested whether the drug synergizes experimental F4ac+ Escherichia coli oral vaccine in stimulating T cells also in the jejunal lamina propria (JLP) and ileal Peyer's patch (IPP) upon virulent challenge. Commercial crossbred pigs weaned at 4 weeks were allocated into two equal groups. The experimental group was i.m. primed with levamisole at an immunostimulatory dose of 2.5 mg/kg once daily, for 3 consecutive days, and controls received saline. Both groups were vaccinated orally with the vaccinal E. coli strain on day 0 and challenged with the virulent E. coli strain 7 days later. All pigs were killed on postchallenge day 6. The results determined by immunophenotyping of isolated cells indicate that priming by levamisole of the vaccinated weaned pigs selectively recruited and activated T cells in the IPP, a lymphoid organ-generating B lymphocytes. The pig IPP is normally populated with up to 5% of CD3+ T cells and CD6 is an activation antigen expressed exclusively by T cells in swine. Therefore, a significantly higher number of CD3+ (P < 0.01) and CD6+ (P < 0.001) cells observed within the IPP follicles of the primed-vaccinated vs. unprimed-vaccinated challenge-infected pigs suggest enhanced T cell-mediated immunity in this B-cell compartment induced by the potentiating action of the drug and vaccine. The ability of levamisole to influence interaction between activated T cells and B cells in the IPP of primed-vaccinated weaned pigs, and the possibility that this interaction plays a role in regulating B-cell maturation within the IPP follicles, are discussed.
最近的研究结果表明，用左旋咪唑对断奶仔猪进行预处理，这些仔猪已通过实验接种疫苗预防断奶后大肠杆菌病（PWC），通过刺激参与细胞介导免疫的肠系膜淋巴结细胞，有助于对激发诱导的临床疾病产生免疫保护。为了更好地理解左旋咪唑诱导针对PWC疫苗接种的保护性黏膜细胞介导免疫反应的机制，测试了该药物在强毒攻击后是否还能协同实验性F4ac +大肠杆菌口服疫苗刺激空肠固有层（JLP）和回肠派伊尔结（IPP）中的T细胞。4周龄断奶的商品杂交猪被分成两组。实验组以2.5 mg/kg的免疫刺激剂量肌肉注射左旋咪唑，每天一次，连续3天，对照组注射生理盐水。两组均在第0天口服接种疫苗大肠杆菌菌株，并在7天后用强毒大肠杆菌菌株进行攻击。所有猪在攻击后第6天处死。对分离细胞进行免疫表型分析得出的结果表明，用左旋咪唑对已接种疫苗的断奶仔猪进行预处理可选择性地募集并激活IPP中的T细胞，IPP是产生B淋巴细胞的淋巴器官。猪的IPP通常含有高达5%的CD3 + T细胞，而CD6是猪中仅由T细胞表达的激活抗原。因此，在预处理-接种疫苗的攻击感染猪的IPP滤泡中观察到的CD3 +（P < 0.01）和CD6 +（P < 0.001）细胞数量显著高于未预处理-接种疫苗的猪，这表明该药物和疫苗的增效作用在这个B细胞区室中诱导了增强的T细胞介导免疫。讨论了左旋咪唑影响预处理-接种疫苗的断奶仔猪IPP中活化T细胞与B细胞之间相互作用的能力，以及这种相互作用在调节IPP滤泡内B细胞成熟中发挥作用的可能性。
